We hypothesized that adenosine, acting via the A1 receptor, is a key factor in the homeostatic control of sleep. The increase in extracellular levels of adenosine during prolonged wakefulness is thought to facilitate the transition to sleep by reducing the discharge activity of wakefulness-promoting neurons in the basal forebrain. Adenosine A1 receptor control of the homeostatic regulation of s...

There is a pronounced decline in sleep with age. Diminished output from the circadian oscillator, the suprachiasmatic nucleus, might play a role, because there is a decrease in the amplitude of the day-night sleep rhythm in the elderly. However, sleep is also regulated by homeostatic mechanisms that build sleep drive during wakefulness, and a decline in these mechanisms could also decrease slee...

Maintaining wakefulness is associated with a progressive increase in the need for sleep. This phenomenon has been linked to changes in synaptic function. The synaptic adhesion molecule Neuroligin-1 (NLG1) controls the activity and synaptic localization of N-methyl-d-aspartate receptors, which activity is impaired by prolonged wakefulness. We here highlight that this pathway may underlie both th...

PURPOSE To describe the SpO2 in wakefulness, sleep and during the apnea-hypopnea in adults living in Bogotá, located at 2640 m above sea level. METHODS Descriptive observational study in adults referred for polysomnogram (PSG). A normal Apnea hypopnea index (AHI) was defined as ≤5 and obstructive sleep apnea (OSA) was classified as mild (AHI 5-15), moderate (AHI 15-30), and severe (AHI >30). ...

Histaminergic neurons play an important role in the regulation of sleep-wake behavior through histamine H(1) receptors (H(1)R). Blockade of the histamine H(3) receptor (H(3)R) is proposed to induce wakefulness by regulating the release of various wake-related transmitters, not only histamine. In the present study, we characterized sleep-wake cycles of H(1)R knockout (KO) mice and their arousal ...

Ghrelin, a gut-brain peptide, is best known for its role in the stimulation of feeding and growth hormone release. In the brain, orexin, neuropeptide Y (NPY), and ghrelin are parts of a food intake regulatory circuit. Orexin and NPY are also implicated in maintaining wakefulness. Previous experiments in our laboratory revealed that intracerebroventricular injections of ghrelin induce wakefulnes...

Sleep is an evolutionarily conserved process that is linked to diurnal cycles and normal daytime wakefulness. Healthy sleep and wakefulness are integral to a healthy lifestyle; this occurs when an organism is able to maintain long bouts of both sleep and wake. Homer proteins, which function as adaptors for group 1 metabotropic glutamate receptors, have been implicated in genetic studies of slee...

Wakefulness and sleep-wake-regulation are complex states, a lot of different components and regulatory mechanisms contribute to these functions. One of the factors involved in sleep wake regulation is the immune system, itself being highly complex, consisting of humoral and cellular components. Molecules that transport the information are, beside others, the “immunotransmitters”, the cytokines....

The noradrenergic (NA-ergic) rapid eye movement (REM)-OFF neurons in locus coeruleus (LC) and cholinergic REM-ON neurons in laterodorsal/pedunculopontine tegmentum show a reciprocal firing pattern. The REM-ON neurons fire during REM sleep whereas REM-OFF neurons stop firing during REM sleep. The cessation of firing of REM-OFF neurons is a pre-requisite for the generation of REM sleep and non-ce...

In mammals, circadian rhythms are controlled by an endogenous clock located in the suprachiasmatic nucleus (SCN). The SCN is part of a wake-promoting pathway in adults involving the dorsomedial hypothalamus (DMH) and locus coeruleus (LC), but little is known about how this circuit develops. Therefore, we examined the neural mechanisms underlying the development of circadian and ultradian sleep-...